#include "SLLst.h"

#include <iostream>

template <class T>

SLLst<T>::~SLLst() {

for (SLLstNode<T> * p;!isEmpty();) {

p=head->next;

delete head;

head=p;

}

}

template <class T>

void SLLst<T>::addToHead(const T & el) {

head=new SLLstNode<T>(el,head);

if(tail == 0)

tail=head;

}

template <class T>

void SLLst<T>::addToTail (const T & el){

if(tail!=0){

tail->next=new SLLstNode<T>(el,0);

tail=tail->next;

}

else

head=tail=new SLLstNode<T>(el);

}

template <class T>

T SLLst<T>::deletFromHead() {

T el= head->info;

SLLstNode<T> * tmp =head;

if (head==tail)

head=tail=0;

else

head=head->next;

delete tmp;

return el;

}

template <class T>

T SLLst<T>::deletFromTail() {

T el = tail->info;

if (head == tail) {

delete head;

head =tail =0 ;

}

else {

SLLstNode<T> * tmp;

for (tmp = head;tmp->next != tail ; tmp=tmp->next) ;

delete tail;

tail =tmp;

tail->next = 0;

}

return el;

}

template <class T>

bool SLLst<T>::isInList(const T & el) const {

for (SLLstNode<T> * tmp = head;tmp!=tail && !(tmp->info==el);tmp=tmp->next) ;

return tmp !=0;

}